可承载CETP多肽表位的颗粒样蛋白表达载体的克隆、表达与分离纯化

Cloning,Expression,Separation and Purification of Particle-Like Protein Loading CETP Polypeptide Epitopes

为了提高多肽表位的免疫原性,利用乙肝病毒核心抗原能够在体外自行组装成病毒样颗粒的特性,将人源胆固醇酯转运蛋白羧基端26个氨基酸连同大肠杆菌DnaK基因C端结构域克隆入乙肝病毒核心抗原的免疫优势决定区,并在大肠杆菌BL-21(DE3)表达,以包含体形式存在,经过洗涤、复性和分子筛纯化,获得纯度达90%以上的目的蛋白。纯化的蛋白免疫新西兰大白兔后能够诱导产生高水平的抗胆固醇酯转运蛋白的抗体,表明乙肝病毒核心抗原能够在体外自发装配成多聚体颗粒,并能够将插入其免疫优势决定区的胆固醇酯转运蛋白(CETP)多肽表位展示于颗粒表面以提高免疫原性,显示出其作为疫苗免疫载体的良好前景。

To enhance the immunity of polypeptide epitopes, the carboxyl-ter minal 26 a mino acids of human cholesteryl ester transfer protein and carboxyl-ter minal domain of DnaK gene were cloned into major immunodo minant region of hepatitis B virus core antigen （HBcAg） based on the characteristics that HBcAg can self-assemble into virus-like particles in vitro, and induce expression of the target protein in E. coli BL21（DE3） in the form of inclusion body. About 90% purity of the recombinant protein was obtained following washing, denaturing and purifying via size-exclusion chromatography. The high level anti-CETP antibody was induced after New Zealand White Rabbits were inoculated with purified recombinant protein, which demonstrated that HBcAg can improve the immunity of CETP polypeptide epitopes merged into major immunodo minant region of HBcAg and displayed on the surface of HBcAg which can self-assemble into polymer particles in vitro. It indicates that the polypeptide carrier is full of promise for vaccination.